Mapping site MapBox has created an interactive cloudless atlas using two year's worth of images taken by Nasa satellites.

More than 339,000 images were collected from Nasa's Moderate-resolution Imaging Spectroradiometer (MODIS) technology, which orbits the Earth attached to satellites.

Cartographers from MapBox then sorted through the images, pixel-by-pixel, finding images taken on cloudless summer days and layered them on top of each other to create the atlas.

A clear image of the UK taken from MapBox's cloudless atlas. MapBox used data collected by Nasa's MODIS satellite that orbits the Sun and captures images of the entire planet every two days. Densely populated cities such as London can be seen, as can the Brecon Beacons in Wales, and the highlands in Scotland

HOW DID MAPBOX DO IT?

Cartographers at the open-source
company then sifted through the images to remove the clouds and haze
caused by the atmosphere to get a clear shot of the ground.

Traditionally, these images would
then be sewn together but this method can leave visible seams in the map
and images next to each might come from different days, so the images
would tie up exactly.

To solve this problem, MapBox took all the images of an area and put them one on top of the other.

The columns of pixels are then reordered based on how cloudy each one showed that area to be.

The team did this for every pixel in the world.

MapBox starts with the data captured by Nasa MODIS system, which can image the entire Earth every one to two days.

According to Chris Herwig, a MapBox data analyst: 'One
of the first sorting processes we had is that we came up with a plan to
obtain images from the summer in the northern and southern hemispheres.

'We only downloaded images from certain dates and from certain locations.'

The MODIS system is attached to a pair of satellites called Terra and Aqua which were launched into orbit in 1999 and 2002 respectively.

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The satellites and the MODIS system images can collect data using the visual field wavelength.

Once MapBox selected the data it wanted, the relevant images were moved from Nasa's servers to MapBox's.

Speaking before the launch, MapBox
cartographer Charlie Lloyd said: 'For the new release we’re processing
two years of imagery, captured from January 1, 2011 through December 31,
2012.

'This amounts to over 339,000 16-megapixel+ satellite images, totaling more than 5,687,476,224,000 pixels.

'We boil these down to a mere 5 billion or so.'

Cloudless atlas shot of the Beaufort Sea and Amundsen Gulf near Canada. The image shows the natural colours of the Canadian tundra. The word tundra usually refers to places where the soil is permanently frozen. Canada's tundra is an example of this permafrost tundra, and there is another in northern Russia

The southern coast of South Africa with the Cape of Good Hope visible in the southwest. Nasa's MODIS technology orbits the Sun on its Terra and Aqua satellites taking images of the Earth. It can capture the entire planet every two days

Nasa's MODIS satellites take images of the entire planet every two days. This picture shows what the images look like when stitched together. They include clouds, atmosphere haze and glints of sunshine. MapBox had to remove all of these elements to create its cloudless atlas. It did this by layering individual pixels from cloudless days around the world on top of each other

Cartographers at the open-source
company then sifted through the images to remove the clouds in order to get a clear shot of the ground.

Traditionally, these images would
then be sewn together but, according to Lloyd, this method can leave visible seams in the map.

Images next to each other might also come from different days, so the images
wouldn't tie up exactly.

To solve this problem, MapBox took all the images of an area and put them one on top of the other.

This image, taken from MapBox's cloudless atlas, shows Australia on a clear day. The red areas show the desert in the Australian Outback. The green sections show forests and areas that get a higher proportion of rain. The map was put together using images taken by Nasa's imaging technology MODIS

The 'boot' of Italy is seen in this image from MapBox's cloudless atlas, with Sicily and Tunisia also visible. More than 339,000 images were taken from two year's worth of Nasa satellite imagery to create the seamless online map

The columns of pixels were then reordered based on how cloudy each one showed that area to be.

'We’ve been able to literally make clouds go away in a way that’s never been done.

Countries Angola, on the coast, and Zambia, shown further inland, feature in this MapBox image. The geology of Angola contains many rocks from the Precambrian age, dating back 541 million years

Some of the images on the cloudless atlas have never been seen clearly before. One example is the island of Borneo, pictured. Borneo is covered in clouds almost all year round so it's been previously difficult to get such a cloud-free image

This image shows the the Nile delta.The green area is a fertile region of land, surrounded by unfertile, dry regions. Almost half of Egypt's population live in the delta. MapBox's Charlie Lloyd said the area is under threat from rising sea levels

The
images from the cloudless atlas give an idea of what astronauts on
board the International Space Station can see on a clear day.

Until recently, MapBox’s maps were created using OpenStreetMap data.

People could then modify these maps and add data using the open-source design software TileMill.

Some areas of Earth are covered in clouds almost all year round meaning traditional satellite imagery is obscured.

Such areas, including the island of Borneo, have never been seen as clearly before as they are on MapBox's cloudless atlas.

MapBox released its first satellite images in December last year, and this latest release takes the layer a step further.

Botswana in south-central Africa is the home of the Okavango delta, pictured in the centre of this MapBox cloudless atlas image. The delta is where the Okavango River reaches a trough created by the location of the tectonic plates, which the continent sits on. All the water that reaches the delta is evaporated so never makes it to the sea

The northern coast of Siberia. The Siberian Traps - a large area of volcanic rock - were formed by a volcanic eruption about 200 million years ago. The eruptions continued for a million years and killed 90% of the population

Only the most densely populated regions can be seen from space. The majority can't be seen without zooming in. This shot shows the Russian city of Moscow. Moscow is what's called a 'megacity' and it is the most populous city in Europe, as well as the 6th largest city in the world